You child has just stepped into his 5th year, and you must have noticed that most kids by the age of 5 are well versed in their mother tongue but not other languages. You start worrying how he is going to fare at school with his peers, teachers, etc. Your child was in a cocoon all these years and all he heard was his parents or grandparents speak in his native language. His outside sphere of influence was limited and so, he might refuse to speak any other language. It’s normal!
What you need to know
But that does not mean he will never learn or will not speak like other kids. First appreciate the fact that he has mastered his native language and be happy about it. Introduce new means to him so that he develops an interest for other languages. Talk to him in small sentences and expose him to a circle that has a new language to offer.
Do not hamper his self confidence, rather tell him how proud you are about his wonderful speech. Language development is just a matter of time. All you need to do is to help him get accustomed to something new without making light of the fact that he knows his native language only. By the way, have you heard a more beautiful lullaby than the one sung in your native language??